1. Field of the Invention
The present invention relates to an air conditioner for a vehicle, and more particularly to an air conditioner for a vehicle in which a variable door is installed at the front and rear sides of an evaporator and heater core so that a moving path of air can be switched.
2. Description of the Related Art
An air conditioner for a vehicle includes a cooling system for cooling the inside of the vehicle and a heating system for heating the inside of the vehicle. The cooling system cools the inside of the vehicle by heat exchange between the evaporator and the external air in the step in which a heat exchange medium discharged by the operation of a compressor circulates to return to the compressor via a condenser, a receiver drier, an expansion valve, and an evaporator. The heating system heats the inside of the vehicle through the heat exchange between the internal/external air and a cooling water in a heater core.
Recently, an air conditioner have been developed in which the external air is supplied to the upper portion of the vehicle and the internal air is supplied to the lower portion, realizing a two layer movement of the internal and external air, so that outer heated air is supplied to window glass through a defrost opening to reduce frost, securing defogging performance, and simultaneously internal heated air is supplied to a leg portion for passengers through a floor opening, improving an inside heating performance of a vehicle.
FIG. 1 shows a conventional air conditioner 10. Referring to the drawing, the air conditioner 10 includes a case 11, an evaporator 12 for cooling air in the case 11, a heater core 13 for heating air in the case 11, a first temp door 14 installed between the evaporator 12 and the heater core 13, a second temp door 15 installed to the rear of the heater core 13, and a plurality of blower fans 16 installed at an entrance of the case 11.
In the operation of the air conditioner 10 having the above structure, the internal air provided by a first blower fan 16a passes through the evaporator 12 and is supplied to the lower portion of the heater core 13 with respect to a partition wall 17. The internal air performs heat exchange at the heater core 13 so as to increase the temperature of the air and is supplied to the inside of a vehicle through a floor opening 111 to heat the inside of the vehicle. The external air provided by a second blower fan 16b passes through the evaporator 12 and is supplied to the upper portion of the heater core 13 with respect to the partition wall 17. The external air performs heat exchange at the heater core 13 and is supplied to window glass through a defrost opening 112, securing a defogging performance.
Here, the partition wall 17 extends from the central rear side of the evaporator 12 toward the central rear side of the heater core 13 and the extended end portion is arranged to direct a vent outlet 113. Since the partition wall 17 is installed between the evaporator 12 and the heater core 13, the internal air and the external air supplied to the inside of a vehicle are prevented from being mixed so that a two layer air flow is formed. However, when the partition wall 17 is fixedly installed at the front and rear sides of the heater core 13, loss of heat due to heat pick up to cold air bypassing the heater core 13 in the maximum cooling mode increases and a large amount of condensed water can be generated on the surface of the case 11 where the cooled air passes.
FIG. 2 shows an air conditioning apparatus 20 for a vehicle disclosed in Japanese Patent Publication No. hei 10-338019. Referring to the drawing, the air conditioning apparatus 20 includes a case 21, an evaporator 22 for cooling air in the case 21, a heater core 23 for heating the air in the case 21, an air door 24 installed between the evaporator 22 and the heater core 23, an auxiliary door 25, and a heated air bypass door 26 installed at an exit of the heater core 23.
In a two layer air flow mode, the air door 24 and the auxiliary door 25 pivot in a direction indicated by a solid line to define a first air path 27 through which the internal air flows and a second air path 28 through which the external air flows. The first air path 27 is connected to a floor opening 211 while the second air path 28 is connected to a defrost opening 213, so that defogging and heating the inside of a vehicle are performed.
However, the air conditioning apparatus 20 requires a space between the end portions of the doors 24 and 25 and the evaporator 22 to secure a pivot space for the air door 24 and the auxiliary door 25. Such space generates a difference in pressure between the upper portion and the lower portion of the case 21, generating a fogging phenomenon. Also, since the air door 24 and the auxiliary door 25 pivot at the same time, an operation range of the air door 24 is restricted and the amount of wind at the exit portion of the evaporator 22 decreases, so that the air door 24 and the auxiliary door 25 are interfered with each other.
To solve the above and other problems, the present invention provides an air conditioner for a vehicle in which a variable door for supplying a two layer air flow by forming a partition wall selectively between the evaporator and the heater core is installed to simplify a path of air so that loss of heat is minimized.
According to one aspect of the present invention, there is provided an air conditioner for a vehicle comprising a case in which a plurality of air paths separated by a separation wall is formed at an end portion of a body, a defrost opening, a vent opening, and a floor opening are formed to supply the air input through the air paths to areas of the inside of the vehicle, and the defrost opening, the vent opening, and the floor opening are selectively open or closed by doors according to a mode, an evaporator installed at an entrance of the air paths to perform heat exchange to make the air passing through the evaporator in a low temperature state so as to cool the inside of the vehicle, a heater core installed at the rear side of the evaporator to perform heat exchange to make the air passing through the heater core in a hot temperature state so as to heat the inside of the vehicle, a first variable wall installed between the evaporator and the heater core to separate the air paths into upper and lower portions, or connect the separated air paths, and open or close a heated air path of the heater core, a temp door installed at the upper portion of the first variable wall between the evaporator and the heater core to adjust a degree of opening or closing of a cooled air path bypassing the heater core, and a second variable wall installed at the rear side of the heater core to separate the air passing through the heater core into upper and lower portions or connect the separated air paths, wherein the first variable wall and the temp door are independently controlled so that a path of the air passing through the evaporator can be varied.
The first variable wall comprises first and second wall surfaces which are inclined at predetermined angles with respect to a rotation shaft installed between a rear side of the evaporator and a front side of the heater core.
A mode of the first variable wall comprises a mode in which a partition wall is formed to separate the air paths for internal and external air into upper and lower portions between the rear side of the evaporator and the front side of the heater core, and a mode in which the air input along the air paths is prevented from being directly supplied to the heater core and simultaneously guiding the supply.
A floor door is installed at the rear side of the heater core and is opened or closed to control the amount of the hot air passing through the heater core to be discharged through the floor opening.
In a two layer air flow mode, the first and second variable walls are set to rotate approximately parallel to a direction in which air flows and the air paths to the rear side of the evaporator is separated into upper and lower layers.